The present invention relates to a novel 1H-pyrrolo-[1,2-b][1,2,4]triazole compound useful as a synthetic intermediate of physiological active substances, including medicines, agricultural chemicals, and the like, as a photographic cyan coupler, as a dye for heat transfer dye-donative materials, and as a precursor of a filter dye for solid state television camera tubes and color liquid crystal televisions. The present invention also relates to a 1H-1,2,-triazole compound that is an intermediate for synthesizing the same efficiently.
Further, the present invention relates to a method for synthesizing cyclohexyl acetates useful, for example, as synthetic intermediates of dyes and as synthetic intermediates of dye-forming couplers, in the field of photographic chemistry.
1H-pyrrolo-[1,2-b][1,2,4]triazole derivatives are described, with respect to their reactivities, generally, in Ukrainski Khimicheskii Zhurnal, Vol. 41, No. 2, pages 181 to 185 (1975), and in Khimiya Geterotsiklicheskikh Scedine nii, No. 2, pages 261 to 267 (1974), and their use as medicines and the like is described in U.S. Pat. Nos. 4,358,457 and 4,962,202. Further, the derivatives are described as photographic magenta couplers and magenta dyes in Nihon Shashin Gakkai Showa 60-Nendo Nenji Taikai Koen Yoshi-shu, JP-A-62-278552 (xe2x80x9cJP-Axe2x80x9d means unexamined published Japanese patent application), JP-A-62-279339, JP-A-1-288835, U.S. Pat. No. 4,910,127 and EP-A-491 197.
Furthermore, U.S. Pat. Nos. 5,256,526, 5,384,236, and 5,547,826 disclose that 1H-pyrrolo-[1,2-b][1,2,4]triazole derivatives can be made into compounds useful as photographic cyan couplers by introducing electron-attracting groups to the 6-position and the 7-position of the 1H-pyrrolo-[1,2-b][1,2,4]triazole derivatives. As methods for synthesizing 1H-pyrrolo-[1,2-b][1,2,4]triazole derivatives having electron-attracting groups at the 6-position and the 7-position, synthetic methods wherein 1H-1,2,-triazole derivatives are used as a starting material are described in JP-A-5-202,004 and JP-A-5-255333. In addition, JP-A-7-48376 and JP-A-8-109172 disclose compounds useful as photographic cyan couplers and methods for synthesizing them, and also their efficient synthetic methods.
On the other hand, many general esterification methods that use condensation of carboxylic acids with alcohols are known, and examples are described in detail in Jikken Kagaku-koza, Vol. 22 (Maruzen, 1992), pp. 43 to 83. Among these, for example, a method for synthesizing an ester by using an equilibrium reaction in the presence of an acid catalyst under dehydration conditions, or a method for synthesizing an ester by using a condensing agent, such as dicyclohexylcarbodiimide and ethyl azodicarboxylate, are often used. Furthermore, there is an acid chloride method for synthesizing an ester, wherein a carboxylic acid is converted by means of thionyl chloride, phosphorus trichloride, or oxalyl chloride, to an acid chloride, and the acid chloride is subjected to addition reaction of an alcohol, in the presence of a base.
The foregoing general esterification methods, however, could not be applied to the synthesis of ester compounds represented by the below-shown formula (IX) using carboxylic acids represented by the below-shown formula (VII) and cyclohexanols represented by the below-shown formula (VI), which are intended to be condensed in the present invention. Namely, the method that uses acid catalysts is accompanied by the problem that large amounts of cyclohexanols are used, and the method that uses condensing agents and the acid chloride method can hardly give the intended ester compounds, because, in the esterification of cyclohexanols, carboxylic acid components are preferentially decomposed. Only one method, using trifluoroacetic anhydride ((CF3CO)2O), described in Journal of Organic Chemistry, Vol. 30, page 927 (1965), has been applied, but the reagent is expensive and the treatment of the waste liquid is complicated, making the method difficult for use as an industrial process.
Therefore, a first object of the present invention is to provide a compound represented by the below-shown formula (I) useful as a photographic cyan coupler.
A second object of the present invention is to provide a synthetic intermediate(s) necessary for the synthesis of the compound represented by formula (I).
A third object of the present invention is to provide an industrial production method for obtaining cyclohexyl acetates represented by the below-shown formula (IX), in a good yield, by reacting cyclohexanols with carboxylic acids under mild reaction conditions.
Other and further objects, features, and advantages of the invention will appear more fully from the following description.
The inventors of the present invention have studied intensively in various ways to develop 1H-pyrrolo-[1,2-b][1,2,4]triazole compounds useful as photographic cyan couplers. The inventors have found that compounds wherein specific substituents are introduced to the 2-position and the 5-position of the pyrrolotriazole skeleton show excellent properties as photographic couplers in view of the hue of the dye formed, the coupling activity, the stain during and after photographic processing, the storage stability of them as couplers, the fastness of their dyes, etc., leading to the completion of the present invention.
The above objects have been attained by providing the compounds represented by the following formulas and the production method.
(1) A 1H-pyrrolo-[1,2-b][1,2,4]triazole compound represented by formula (I): 
wherein, in formula (I), R represents an alkyl group; R1, R2, R3, R1xe2x80x2, R2xe2x80x2, and R3xe2x80x2 each represent a hydrogen atom or an alkyl group; R1 and R2, and R1xe2x80x2 and R2xe2x80x2, may bond together to form a ring, respectively; R4 represents a hydrogen atom or an alkyl group, and X represents a heterocyclic group, a substituted amino group, or an aryl group.
(2) A 1H-1,2,-triazole compound represented by formula (II): 
wherein, in formula (II), R represents an alkyl group; R1, R2, R3, R1xe2x80x2, R2xe2x80x2, and R3xe2x80x2 each represent a hydrogen atom or an alkyl group; R1 and R2, and R1xe2x80x2 and R2xe2x80x2, may bond together to form a ring, respectively; R4 represents a hydrogen atom or an alkyl group, and R5 represents a hydrogen atom or an alkyl group.
(3) A 1H-1,2,4-triazole compound represented by formula (III): 
wherein, in formula (III), R represents an alkyl group; R1, R2, R3, R1xe2x80x2, R2xe2x80x2, and R3xe2x80x2 each represent a hydrogen atom or an alkyl group; R1 and R2, and R1xe2x80x2 and R2xe2x80x2, may bond together to form a ring, respectively; R4 represents a hydrogen atom or an alkyl group, and W represents a halogen atom.
(4) A method for producing an ester compound represented by the following formula (IX), by reacting cyclohexanols represented by the following formula (VI) and carboxylic acids represented by the following formula (VII), using a carboxylic acid anhydride represented by the following formula (VIII): 
wherein R11 represents a hydrogen atom or an alkyl group; R12, R13, R14, R12xe2x80x2, R13xe2x80x2, and R14xe2x80x2, which are the same or different, each represent a hydrogen atom or an alkyl group, R12 and R13, and R12xe2x80x2 and R13xe2x80x2, may bond together to a form ring, respectively; R15 and R16, which are the same or different, each represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group, with at least one of R15 and R16 being a hydrogen atom; R17 represents an aliphatic group or an aryl group; R18 and R19, which are the same or different, each represent a hydrogen atom, a halogen atom, an alkyl group, or an aryl group; R18 and R19 may bond together to form a ring; M represents a hydrogen atom, an alkali metal, or an alkali earth metal; and n is an integer of 1 or 2.
(5) The method of producing an ester compound as stated in the above (4), wherein the reaction is carried out in the presence of a base.
(6) The method of producing an ester compound as stated in the above (4) or (5), wherein the carboxylic acid anhydride represented by formula (VIII) is an acetic anhydride.
(7) The method of producing an ester compound as stated in the above (4), (5), or (6), wherein the compound represented by formula (IX) is a 3-(4-t-butylphenyl)-1H-1,2,4-triazol-5-yl-acetic acid ester compound represented by the following formula: 
wherein R11, R12, R13, R14, R12xe2x80x2, R13xe2x80x2, R14xe2x80x2, R15, and R16 each have the same meanings as defined above.
(8) The method for producing an ester compound as stated in the above (4), (5), (6), or (7), wherein the compound represented by formula (IX) is a 3-(4-t-butylphenyl)-1H-1,2,4-triazol-5-yl-acetic acid ester compound represented by the following formula: 
Herein, in the present invention, a group on the compound includes both a group having a substituent thereon and a group having no substituent (i.e. an unsubstituted group), unless otherwise specified.
Hereinbelow, the present invention is described in detail.
In formulae (I) to (III), R represents a straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms, or a cyclic alkyl group (preferably having 3 to 8 carbon atoms), and preferably a straight-chain or branched-chain alkyl group having 1 to 8 carbon atoms, and more preferably a branched-chain alkyl group having 4 to 8 carbon atoms. Particularly preferably the alkyl group is a t-butyl group.
In formulae (I) to (III), R1, R2, R3, R1xe2x80x2, R2xe2x80x2, and R3xe2x80x2, which may be the same or different, each represent a hydrogen atom, or a straight-chain or branched-chain alkyl group having 1 to 24 carbon atoms, or a cyclic alkyl group (preferably having 3 to 8 carbon atoms). Preferably R1, R2, R3, R1xe2x80x2, R2xe2x80x2, and R3xe2x80x2 each represent a straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms, or a cyclic alkyl group (preferably having 3 to 8 carbon atoms), and more preferably a straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms, or a cyclic alkyl group (preferably having 3 to 8 carbon atoms), such as methyl, ethyl, propyl, and cyclohexyl. R1 and R2, and R1xe2x80x2 and R2xe2x80x2, may bond together to form a ring, respectively, and, for example, preferably R1 and R2, and R1xe2x80x2 and R2xe2x80x2, form, respectively, a lower alkylene group having 1 to 12 carbon atoms, and preferably they form methylene, ethylene, propylene, butylene, pentylene, or hexylene. A particularly preferable group represented by each of R1, R2, R3, R1xe2x80x2, R2xe2x80x2, and R3xe2x80x2 is a methyl group.
In formulae (I) to (III), R4 represents a hydrogen group, or a straight-chain or branched-chain alkyl group having 1 to 36 carbon atoms, or a cyclic alkyl group (preferably having 3 to 8 carbon atoms), preferably a straight-chain or branched-chain alkyl group having 1 to 24 carbon atoms, and further preferably 1 to 12 carbon atoms, or cyclic alkyl group (preferably having 3 to 8 carbon atoms), and still further preferably a straight-chain or branched-chain alkyl group having 1 to 4 carbon atoms, such as methyl, ethyl, propyl, isopropyl, isobutyl, t-butyl, octyl, octadecyl, and cyclohexyl. A particularly preferable alkyl group is a methyl group.
In formula (II), R5 represents a hydrogen atom or a straight-chain or branched-chain alkyl group having 1 to 4 carbon atoms, and preferably a straight-chain alkyl group having 1 to 2 carbon atoms. A particularly preferable alkyl group is a methyl group.
In formula (III), W represents a halogen atom, preferably a chlorine atom, a bromine atom, or an iodine atom, and particularly preferably a bromine atom.
In formula (I), X represents a heterocyclic group, a substituted amino group, or an aryl group. The heterocyclic ring is preferably a 5- to 8-membered ring having a nitrogen atom, an oxygen atom, or a sulfur atom, and the ring includes 1 to 36 carbon atoms (preferably 1 to 8 carbon atoms) in all, including the carbon atoms in the substituent, if any, and more preferably the heterocyclic ring is a 5- or 6-membered ring bonded through the nitrogen atom, with particular preference given to a 6-membered ring.
Specific examples of X include imidazole, pyrazole, triazole, lactam compounds, piperidine, pyrrolidine, pyrrole, morpholine, pyrazolidine, thiazolidine, and pyrazoline. Preferably X represents morpholine and piperidine, with particular preference given to morpholine.
As the substituent on the substituted-amino group, an aliphatic group, an aryl group, or a heterocyclic group can be mentioned. The aliphatic group includes a straight-chain or branched-chain alkyl group having 1 to 12 carbon atoms, or a cyclic alkyl group (preferably having 3 to 8 carbon atoms), and preferably a straight-chain alkyl group having 1 to 8 carbon atoms, each of which may be substituted by a cyano group, an alkoxy group (e.g. methoxy), an alkoxycarbonyl group, chlorine, a hydroxyl group, a carboxyl group, or the like. As the substituted amino group, a di-substituted amino group is preferred to a mono-substituted amino group.
Specific examples of the substituted amino group include dicyanoethylamino, dimethoxyethylamino, diallylamino, diphenylamino, dioctylamino, and dicyclohexylamino.
The aryl group represented by X is preferably an aryl group having 6 to 36 carbon atoms, and more preferably a phenyl group or a naphthyl group. Specific examples of the aryl group include phenyl, 4-t-butylphenyl, 2-methylphenyl, 2,4,6-trimethylphenyl, 2-methoxyphenyl, 4-methoxyphenyl, 2,6-dichlorophenyl, 2-chlorophenyl, 2,4-dichlorophenyl, and naphthyl.
Hereinbelow, specific examples of the compounds represented by formula (I), (II), or (III) are shown, but the present invention is not limited to them. 
Now, general methods for synthesizing the compounds represented by one of formulae (I), (II), and (III) are described by reference to the below-shown scheme. The below-described Scheme 1 is a scheme in which Compound e, as the compound represented by formula (IV), Compound (III)-(1), as the compound represented by formula (III), methyl cyanoacetate, as cyanoacetates, Compound (II)-(1), as the compound represented by formula (II), and Compound (I)-(1), as the compound represented by formula (I), are used. As is shown in this Scheme 1, the compound represented by formula (III) can be obtained by halogenating the compound represented by the below-shown formula (IV). (Hereinafter, this step is referred to as Step 1.)
Further, the compound represented by formula (II) can be obtained by reacting the compound represented by formula (III) and cyanoacetates, by using a suitable organic base. (Step 2)
One compound represented by formula (II) in which R5 is a hydrogen atom, can be easily obtained by hydrolyzing the ester product obtained in the above manner. (Step 3)
By allowing the thus-obtained compound represented by formula (II) (R5 is hydrogen) to be subjected to the action of an acid halide (having the below-shown formula (V)) in the presence of a base, a 1H-pyrrolo-[1,2,b][1,2,4]triazole derivative represented by formula (I) can be obtained. (Step 4) 
wherein R1, R2, R3, R4, R1xe2x80x2, R2xe2x80x2, R3xe2x80x2, R, and X have the same meanings as those of formula (I).
Now, each of the steps is described in detail.
First, Step 1 is described in detail. In Step 1, the triazole derivative represented by formula (IV) can be synthesized by known methods; for example, methods described in J.C.S., 1961, page 518; J.C.S., 1962, page 5149; Angew, Chem, Vol. 72, page 956 (1960); Berichte., Vol. 97, page 3436 (1964), etc., methods described in documents cited in those documents, or similar methods. Preferably, the triazole derivative represented by formula (IV) can be synthesized by the method of the present invention described herein.
Examples of the halogenating agent in the halogenation of Step 1 include sulfuryl chloride, copper(II) chloride, N-chlorosuccinimide, N-bromosuccinimide, 1,3-dibromo-5,5-dimethylhidantoin, bromide, and pyridinium bromide perbromide, with preference given to sulfuryl chloride, bromine, 1,3-dibromo-5,5-dimethylhidantoin, and pyridinium bromide perbromide, and more preference given to bromine and 1,3-dibromo-5,5-dimethylhidantoin.
The molar ratio of the halogenating agent to formula (IV) in Step 1 is generally from 0.5 to 5, and preferably 0.5 to 2.0.
As the solvent used in Step 1, methylene chloride, chloroform, 1,2-dichloroethane, carbon tetrachloride, tetrahydrofuran, dioxane, benzene, toluene, ethyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, acetonitrile, and dimethyl sulfoxide can be mentioned. Preferable solvents are toluene, ethyl acetate, and acetonitrile.
In Step 1, if the reaction is carried out using a suitable base, the yield can be increased. As the base, triethylamine, diisopropylethylamine, pyridine, 2,6-lutidine, 2,4-lutidine, 2,3-lutidine, 2,5-lutidine, 2,4,6-collidine, 2-picoline, 3-picoline, 4-picoline, imidazole, diethylaniline, piperidine, morpholine, N-methylmorpholine, tetramethylguanidine, and tetraphenylguanidine can be mentioned, with preference given to pyridine, 2,6-lutidine, 2,4,6-collidine, and 2-picoline.
The amount of the base is such that the molar ratio thereof to the compound represented by formula (IV) is generally from 0.5 to 5.0, and preferably from 0.5 to 2.0.
In Step 1, the reaction temperature is generally xe2x88x9210 to 80xc2x0 C., and preferably 0 to 30xc2x0 C. The reaction time is generally 1 min to 24 hours, preferably 10 min to 10 hours, and more preferably 30 min to 6 hours.
Now, Step 2 is described in detail.
As the base used in the nucleophilic substitution reaction of the compound represented by formula (III) and the cyanoacetates, n-butyllithium, t-butyllithium, lithium diisopropylamide, sodium hydride, potassium hydride, lithium hydride, t-butoxypotassium, sodium methoxide, sodium ethoxide, potassium methoxide, lithium methoxide, tetramethylguanidine, tetraphenylguanidine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), sodium hydroxide, and potassium hydroxide can be mentioned, with preference given to sodium hydride, sodium methoxide, sodium ethoxide, and t-butoxypotassium.
The molar ratio of the base used in Step 2 to the cyanoacetates is generally from 1.0 to 10, preferably 1.0 to 5.0, and more preferably 1.5 to 3.0.
The molar ratio of the cyanoacetates used in Step 2 to the compound represented by formula (III) is generally from 1.0 to 10, preferably from 1.0 to 5.0, and more preferably from 1.5 to 3.0.
As the solvent used in Step 2, hexane, methanol, methylene chloride, chloroform, 1,2-dichloroethane, carbon tetrachloride, tetrahydrofuran, dioxane, benzene, toluene, ethyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, acetonitrile, and dimethyl sulfoxide can be mentioned, with preference given to acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, ethyl acetate, hexane, and methanol.
In Step 2, the reaction temperature is generally xe2x88x9278 to 150xc2x0 C., preferably xe2x88x9240 to 60xc2x0 C., and more preferably 20 to 30xc2x0 C.
The reaction time is generally 1 min to 24 hours, preferably 10 min to 10 hours, and more preferably 30 min to 6 hours.
In the reaction in Step 2, the order of the addition is preferably carried out as follows: the compound of formula (III) previously dissolved in a solvent is added, dropwise, into the solvent containing the cyanoacetates and the base.
Step 3 is now described in detail.
The hydrolysis of the ester moiety of the compound represented by formula (II) can be carried out easily in a usual manner. As a general method, a method wherein a base is used can be employed. In that case, as the base, for example, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, barium hydroxide, or ammonium carbonate is used, with preference given to sodium hydroxide and potassium hydroxide.
As the reaction medium, those solvents mentioned above are preferable, and more preferably a water/methanol mixed solvent is used.
The reaction temperature is generally 0 to 100xc2x0 C., preferably 15 to 80xc2x0 C., more preferably 30 to 80xc2x0 C., and further preferably 40 to 80xc2x0 C.
The reaction time is generally 1 min to 24 hours, preferably 10 min to 10 hours, and more preferably 30 min to 3 hours.
Now, Step 4 is described in detail.
As the base used in Step 4, can be mentioned, for example, triethylamine, diisopropylethylamine, pyridine, 2,6-lutidine, 2,-lutidine, 2,3-lutidine, 2,5-lutidine, 2,4,6-collidine, 2-picoline, 3-picoline, 4-picoline, imidazole, diethylaniline, piperidine, morpholine, N-methylmorpholine, tetramethylguanidine, tetraphenylguanidine, DBU, DBN, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate, with preference given to pyridine, triethylamine, lutidines, collidine, and picolines.
The molar ratio of the base used in Step 4 to the compound represented by formula (II) (R5=H) is generally from 0.1 to 10, preferably 1.0 to 8.0, and more preferably 2.0 to 6.0.
Specific examples of the acid halides represented by formula (V) used in Step 4 include benzoyl chloride, 2-methylbenzoyl chloride, 2-methoxybenzoyl chloride, 2,6-dichlorobenzoyl chloride, dimethylcarbamic acid chloride, diethylcarbamic acid chloride, diphenylcarbamic acid chloride, dicyclohexylcarbamic acid chloride, dicyanoethylcarbamic acid chloride, dimethoxyethylcarbamic acid chloride, diallylcarbamic acid chloride, morpholincarbonyl chloride, and 4-methoxycarbonylisonicotincarbonyl chloride.
The molar ratio of the acid halide represented by formula (V) used in Step 4 to the compound represented by formula (II) is generally from 1.0 to 10, preferably from 1 to 5, and more preferably from 2 to 4.
As the solvent used in Step 4, methylene chloride, chloroform, 1,2-dichloroethane, carbon tetrachloride, tetrahydrofuran, dioxane, benzene, toluene, ethyl acetate, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, acetonitrile, and dimethyl sulfoxide can be mentioned, with preference given to acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, ethyl acetate, and toluene.
In Step 4, the reaction temperature is generally xe2x88x9278 to 100xc2x0 C., preferably xe2x88x9220 to 80xc2x0 C., and more preferably 0 to 50xc2x0 C.
The reaction time is generally 1 min to 24 hours, preferably 15 min to 10 hours, and more preferably 30 min to 6 hours.
Now, the production method of the intermediate of the present invention is described in detail.
In formula (VI), R11 represents a hydrogen atom, or a straight-chain, branched-chain or cyclic alkyl group having 1 to 36 carbon atoms, such as methyl, ethyl, propyl, isopropyl, isobutyl, t-butyl, octyl, octadecyl, or cyclohexyl.
R11 preferably represents a straight-chain or branched-chain alkyl group having preferably 1 to 24 carbon atoms and more preferably 1 to 12 carbon atoms, or a cyclic alykyl group (preferably having 3 to 8 carbon atoms), which may be substituted. Preferable substituents are a halogen atom, a hydroxyl group, a cyano group, a nitro group, a carboxyl group, an amino group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an acylamino group, an alkylamino group, an anilino group, a ureido group, a sulfamoylamino group, an alkylthio group, an arylthio group, a heterocyclic thio group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonamido group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a carbamoyloxy group, a silyloxy group, an imido group, a sulfinyl group, and a phosphonyl group. Particularly preferably, R11 represents a methyl group.
R12, R13, R14, R12xe2x80x2, R13xe2x80x2, and R14xe2x80x2, each represent a hydrogen atom, a straight-chain or branched-chain alkyl group having 1 to 24 carbon atoms, or a cyclic alkyl group (preferably having 3 to 8 carbon atoms).
R12, R13, R14, R12xe2x80x2, R13xe2x80x2, and R14xe2x80x2, which are the same or different, each represent a straight-chain or branched-chain alkyl group preferably having 1 to 12 carbon atoms, and more preferably 1 to 6 carbon atoms, or a cyclic alkyl group (preferably having 3 to 8 carbon atoms), such as methyl, ethyl, propyl, and cyclohexyl. R12 and R13, and R12xe2x80x2 and R13xe2x80x2 may bond together to form a ring (for example a 3- to 6-membered ring, preferably a 6-membered ring, such as cyclohexyl), respectively. Particularly preferably, R12, R13, R14, R12xe2x80x2, R13xe2x80x2, and R14xe2x80x2 each represent a methyl group.
In some cases, the compounds used in the present invention have sterochemical isomers, and in the present invention, use can be made of each of the compounds in the form of mixtures of stereoisomers or in the form of a single stereoisomer.
Specific examples of the compound (VI) are shown below, but the present invention is not restricted to them. 
Now, formula (VII) is described.
R15 and R16, which are the same or different, each represent a hydrogen atom, a halogen atom (e.g., a chlorine atom, a bromine atom, and an iodine atom), an alkyl group [a straight-chain, branched-chain or cyclic alkyl group having 1 to 36 carbon atoms (preferably having 1 to 24 carbon atoms), which may be substituted by such a substituent as described for R11, e.g., methyl, ethyl, propyl, butyl, isopropyl, octyl, hexadecyl, cyclohexyl, and 1-cyano-(methoxycarbonyl)methyl], or an aryl group [an aryl group having 6 to 36 carbon atoms (preferably having 6 to 24 carbon atoms), which aryl group may be substituted by such a substituent as described for R11, e.g., a phenyl group].
Preferably at least one of R15 and R16 represents a hydrogen atom, and more preferably both of R15 and R16 each represent a hydrogen atom.
R17 represents an aliphatic group or an aryl group. M represents a hydrogen atom (M=H and n=1), an alkali metal (M=Li, Na, K, Rb, or Cs, and n=1), or an alkali earth metal (M=Be, Mg, Ca, Sr, or Ba, and n=2).
The aliphatic group represented by R17 is, for example, a straight-chain alkyl group, a branched-chain alkyl group, an aralkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, and a cycloalkenyl group, having 1 to 36 (preferably 1 to 24) carbon atoms, any of which groups may have such a substituent as described for R11; more specifically, for example, methyl, ethyl, propyl, isopropyl, t-butyl, t-amyl, octyl, octadecyl, vinyl, cyclohexyl, 4-pentylcyclohexyl, cyclohexenyl, and propargyl.
The aryl group represented by R17 is an aryl group having 6 to 36 carbon atoms (preferably 6 to 24 carbon atoms), with preference given to a phenyl group or a naphtyl group. The aryl group may have such a substituent as described for R11, for example, phenyl, 3-nitrophenyl, 4-nitrophenyl, 4-chlorophenyl, 3,5-dichlorophenyl, 4-methoxyphenyl, 4-t-butylphenyl, 3-(2-octoxy-5-t-octylphenylsulfonamido)-4-methoxyphenyl, and 3-nitro-4-methylphenyl.
Preferably M represents a hydrogen atom (H), lithium (Li), sodium (Na), potassium (K), magnesium (Mg), or calcium (Ca), and more preferably a hydrogen atom (H), sodium (Na), or potassium (K).
Specific examples of the carbonic acids represented by formula (VII) are shown below, but the present invention is not restricted to them. 
Now, formula (VIII) is described.
R18 and R19, which are the same or different, each represent a hydrogen atom, a halogen atom (preferably a chlorine atom, a bromine atom, and an iodine atom, and more preferably a chrorine atom), an alkyl group [a straight-chain or branched-chain alkyl group having 1 to 36 carbon atoms (preferably having 1 to 24 carbon atoms), or a cyclic alkyl group (preferably having 3 to 8 carbon atoms), each of which may be substituted by such a substituent as described for R11, e.g., methyl, ethyl, propyl, butyl, t-butyl, isopropyl, hexyl, octyl, hexadecyl, cyclohexyl, and cyclopentyl], or an aryl group [an aryl group having 6 to 36 carbon atoms (preferably having 6 to 24 carbon atoms), which aryl group may be substituted by such a substituent as described for R11, e.g., a phenyl group]. R18 and R19 may bond together to form a ring. Most preferably R18 and R19 each represent a hydrogen atom.
Specific examples of the carboxylic acid anhydrides represented by formula (VIII) that can be used in the present invention, are shown below, but the present invention is not restricted to them. 
The production method of the present invention is shown by the following Scheme (i).
In the present invention, if the compound represented by formula (VIII) is acetic anhydride, a compound represented by the below-shown formula (X) is isolated. Therefore, the ester compound represented by formula (IX) is synthesized via the deacetylation reaction of the compound represented by formula (X). The compound (X) may be isolated, or the compound represented by formula (VI) and the compound represented by formula (VII) are condensed and the compound (IX) may be derived by the deacetylation reaction without treating the reaction system. The deacetylation reaction may be carried out under either acidic conditions or alkaline conditions. 
To carry out the deacetylation under acidic conditions, for example, hydrochloric acid, sulfuric acid, trifluoroacetic acid, p-toluenesulfonic acid, or methanesulfonic acid can be used. To carry out the deacetylation under alkaline conditions, for example, aqueous ammonia, sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, potassium ethylate, or potassium t-butoxide can be used.
Specific examples of the ester compound represented by formula (IX) that can be synthesized by the method of the present invention are shown below, but the present invention is not restricted to them. 
In the present invention, the reaction molar ratio of the cyclohexanols represented by formula (VI) to the carboxylic acids represented by formula (VII) follows the stoichiometric amounts, and it is preferably 10:1 to 1:1, and more preferably 3:1 to 1:1.
The reaction in the method of the present invention is preferably carried out in the presence of a base. The base may be either an organic base or an inorganic base.
As the organic base, guanidines (e.g. tetramethylguanidine and diphenylguanidine), trialkylamines (e.g. triethylamine, ethyldiisopropylamine, tributylamine, 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), hexamethyltetramine, quinuclidine, 4-ethylmorpholine, and N-methylpiperidine), aliphatic polyamines (e.g. tetramethylethylenediamine and tetraethylethylenediamine), aromatic amines (e.g. dimethylaniline and diethylaniline), and heterocyclic amines (e.g. pyridine, 2-picoline, 2-ethylpyridine, 3-picoline, 2,6-lutidine, pyridazine, pyrimidine, triazine, pyrazine, quinoline, isoquinoline, pyrrole, pyrazole, imidazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, indole, and benzotriazole) can be used. Preferably, trialkylamines, aromatic amines, and heterocyclic amines are used; more preferably trialkylamines and heterocyclic amines are used, and further more preferably trialkylamines are used.
Atoms other than hydrogen atoms and carbon atoms constituting these heterocyclic rings are oxygen, nitrogen, and sulfur atoms. The ring may be either a monocyclic ring or a condensed ring, with preference given to a monocyclic ring. The number of members of the ring is preferably 5 or 6.
As the inorganic base, for example, sodium formate, lithium oxalate, lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, lithium acetate, sodium acetate, potassium acetate, sodium monochloroacetate, potassium benzoate, sodium benzoate, sodium hydrogencarbonate, and potassium hydrogencarbonate can be used. Preferably sodium carbonate, potassium carbonate, sodium acetate, and potassium acetate are used, and more preferably potassium carbonate and potassium acetate are used.
The amount of the base to be used is suitably generally 0.1 to 10 mol equivalents, preferably 0.5 to 5.0 mol equivalents, and more preferably 1.0 to 3.0 mol equivalents, for the compound of formula (VI).
The amount of the carboxylic acid anhydride represented by formula (VIII) to be used is suitably generally 0.5 to 20 mol equivalents, preferably 2 to 10 mol equivalents, and more preferably 3 to 6 mol equivalents, per mol of the compound of formula (VI).
When the carboxylic acid anhydride represented by formula (VIII) is acetic anhydride, the amount of the acid or alkali to be used, as a deacetylating agent is suitably generally 1 to 20 mol equivalents, preferably 2 to 10 mol equivalents, and more preferably 4 to 7 mol equivalents, per mol of the compound of formula (VI).
As the solvent, such a solvent as methylene chloride, 1,2-dichloroethane, chloroform, benzene, toluene, ethyl acetate, acetonitrile, nitromethane, tetrahydrofuran, diethyl ether, and diglyme can be used, with preference given to benzene, toluene, ethyl acetate, and acetonitrile, more preference given to ethyl acetate, acetonitrile, and toluene, and further preference given to ethyl acetate and toluene. The amount of the solvent to be used is suitably generally 2 to 50 times, and preferably 3 to 10 times, the weight amount of the compound of formula (VI).
The reaction temperature is generally xe2x88x9240 to 80xc2x0 C., and preferably 20 to 60xc2x0 C.
The reaction time is generally 0.1 to 10 hours, and preferably 1 to 5 hours.
To add the reagents, in the case using a base, there are a method in which the base is added to a solution of the cyclohexanols (VI) and the carboxylic acids (VII), and then the carboxylic acid anhydrides (VIII) is added, and a method in which the carboxylic acids (VII) are added to a solution of the cyclohexanols (VI) and the carboxylic acid anhydrides (VIII), and then the base is added, with preference given to the former method.
The 1H-pyrrolo-[1,2-b][1,2,4]triazole compounds represented by formula (I) of the present invention are novel compounds, and they can be used in various applications. The 1H-pyrrolo-[1,2-b][1,2,4]triazole compounds represented by formula (I) of the present invention are, for example, excellent in all of the following: as a photographic coupler, in storage stability, coupling activity, hue and fastness of the dye formed therefrom, prevention of stain during and after the processing, etc. Additionally stated, the compound represented by formula (I) can be synthesized from the compound represented by formula (III) without requiring an isolating step. This means that there is a considerable cost merit with regard to production.
Further, the 1H-1,2,4-triazole compounds represented by formula (II) or (III) of the present invention are useful as synthetic intermediates of the compounds represented by formula (I).
The compound represented by formula (I) of the present invention is excellent as a photographic cyan coupler. Particularly the cyan dye formed from this compound is excellent in hue, as well as in fastness to light.
Further, according to the method of the present invention, cyclohexyl=1H-1,2,4-triazole-5-yl-acetate compounds can be obtained, in a good yield, by condensing cyclohexanols with carboxylic acids with the use of a carboxylic acid anhydride under mild conditions.
The cyclohexyl 1H-1,2,4-triazole-5-yl-acetates obtained by the method of the present invention are useful as synthetic intermediates or their precursors of the 1H-pyrrolo-[1,2-b][1,2,4]triazole compounds represented by formula (I) of the present invention.